The invention relates to a design support system, and more particularly, to a design support system which preliminarily estimates unknown connection data prior to actual connection of a conductor to a connector terminal, to thereby support the design of a connection.
A method for caulking and crimping a conductor by means of, e.g., a barrel provided on a connector terminal, and a method for press-fitting a conductor sheathed with an insulation cladding into a slot formed in the connector terminal have hitherto been available as a method for electrically connecting a conductor to a connector terminal.
First, a method for connecting a conductor to a connector terminal by means of crimping will now be described. The connector terminal used for crimping connection usually assumes constructions such as shown those in FIGS. 2A and 2B. As illustrated, a connector terminal 12 has a conductor barrel 12A and an insulator barrel 12B.
As shown in FIGS. 2C and 2D, the previously-described conductor barrel 12A and the previously-described insulator barrel 12B of the connector terminal 12 and a conductor 11A are crimped with a crimper 14A and an anvil 13. Subsequently, pressure is applied to the conductor barrel 12A, the insulator barrel 12B, and the conductor 11A, whereby the conductor 11A is caulked and crimped with the conductor barrel 12A. Further, an insulation cladding 11B sheathing the conductor 11A is caulked and crimped (as shown in FIG. 213) with the insulator barrel 12B, whereby the connector terminal 12 is connected to the conductor 11A in the manner shown in FIG. 2F.
FIG. 11 shows relationships existing between the height of a crimp C/H (see FIG. 2F) achieved after crimping, and adhesion force F1 and contact resistance R1 existing between the crimped conductor 11A and the connector terminal 12.
As illustrated, the adhesion force F1 possesses an upwardly-bulging nonlinear characteristic with respect to the crimp height C/H. Hence, the adhesion force F1 is considered to be usable within a given range of the crimp height C/H. Similarly, the contact resistance R1 possesses a rightwardly-climbing nonlinear characteristic with respect to the crimp height C/H. Therefore, the contact resistance R1 is considered to be usable within a given range of crimp height C/H. In view of a relationship between the adhesion force F1 and the contact resistance R1, which have these nonlinear characteristics with respect to crimp height, the range of crimp height C/H (i.e., an optimal crimp height shown in FIG. 11) for which the adhesion force F1 and the contact resistance R1 can be used is limited.
When a new connection is designed, the conductor 11A, the connector terminal 12, and the anvil 13 or the crimper 14 have hitherto been designed. After crimp connection has been actually effected through use of the thus-designed conductor 11A, the connector terminal 12, and the anvil 13/crimper 14A, the crimp height C/H, the adhesion force F1, and the contact resistance R1 are measured. An evaluation is made as to whether or not the crimp height C/H—at which optimal adhesion force F1 and contact resistance R1 are to be achieved—is obtained. If the crimp height C/H is not obtained, the foregoing operations are again repeated after a new conductor 11A, a new connector terminal 12, and anew anvil 13/new crimper 14 have been designed.
Next, a method for connecting a conductor to a connector terminal through press-fitting (pressure-welding) will be described. A connector terminal used for press-fitting connection usually assumes a configuration such as that shown in FIG. 8. As illustrated, the connector terminal 12 has an electrical connection section 12C having a pair of pressure-welding blades (FIG. 8A shows a single pressure-welding blade, and FIG. 8B shows two pressure-welding blades).
A slot 12D is formed between the pair of pressure-welding blades. The width W of the slot is designed to become narrower than the outer diameter of the conductor 11A sheathed with the insulation cladding 11B. When the conductor 11A sheathed with the insulation cladding 11B is press-fitted into the slot 12D, the insulation cladding 11B is broken with the pressure-welding blades, whereupon the pressure-welding blades come into contact with the conductor 11A, and the connector terminal 12 is connected to the conductor 11A.
When the slot width W is made constant, there are achieved relationships between the crimp height “l” achieved after press-fitting, and drawing force F2 and contact resistance R21, R22 (R21 denotes the maximum contact resistance, and R22 denotes mean contact resistance) existing between the conductor 11A and the connector terminal 12, such as those shown in FIG. 10A. When the crimp height “l” is made constant, there are achieved relationships between the slot width W obtained before press-fitting and the drawing force F2 and contact resistance R21, R22 existing between the press-fitted conductor 11A and the connector terminal 12, such as those shown in FIG. 10B.
As illustrated, the drawing force F2 has an upwardly concave nonlinear characteristic with respect to the crimp height “l” and the slot width W. Hence, the drawing force F2 is considered to be usable within a given range of the crimp height “l” and that of the slot width W. Similarly, the contact resistances R21, R22 possess the rightwardly-climbing nonlinear characteristics with respect to the crimp height “l” and the slot width W. Hence, the contact resistances R21, R22 are considered to be usable within a given range of crimp height “l” and that of the slot width W.
In view of the relationships between the drawing force F2 and the contact resistance R21, R22, all having the nonlinear characteristics, the range of the crimp height “l” and that of the slot width W (i.e., an optimal crimp height and an optimal slot width shown in FIG. 10) in which the drawing force F2 and the contact resistances R21, R22 are usable is limited.
For instance, when a new connection is designed, the conductor 11A and the connector terminal 12 are conventionally designed. After press-fitting connection has actually been effected through use of the thus-designed conductor 11A and the connector terminal 12, the crimp height “l,” the slot width W, the drawing force F1, and the contact resistance R1 are measured. An evaluation is made as to whether or not the crimp height “l” and the slot width W—at which the optimal drawing force F1 and the optimal contact resistances R21, R22 are achieved—is obtained. When not obtained, the foregoing operations are repeated after the conductor 11A and the connector terminal 12 have been newly designed.
However, the conventional design of connection between the conductor and the connector terminal involves a necessity for achieving an optimal connection by iteration of trial and error operations, such as the aforementioned design, actual connection, and evaluation. Therefore, when a person who is less experienced in design attempts to design a connection, there arises consumption of a longer time until a desired connections implemented. This in turn renders a design period longer and adds to design costs.